need info on Boss BV9560B

hey all, this is my first post here, hopefully not my last. i'll start by saying, i'm not too savvy with car audio and don't really have a "system" in my truck, although i'd like to someday. my truck is a 2004 GMC Sierra Z71 rcsb, and up until today, i had a stock deck. i have a set of Kicker 6.5" door speakers and stock rear speakers, sounds decent but no bass (as you might expect, lol).

well, for Christmas my wife got me a Boss BV9560B head unit to replace my stock head unit. i know it's not the best deck (pretty much low end), but she got a good deal on it and i really appreciated the thought...anyhow, i don't really know anything about the deck, and i'm having a slight issue...and was wondering if i could get some help...

first, on two screens, there is a password. the factory sets this password as "0000", but i've tried this and it doesn't work. the HU was brand new in the plastic so i'm not real sure what's up. i've tried "1234" and a few other combos too, nada.

secondly, are there any tips/tricks with this thing? i mean, the "user's manual" doesn't really tell much and i'll admit i'm new to this kind of deck...

sorry for the nOOb questions and i appreciate any help you could give me!